Can WD-40 be used to refill a Zippo lighter?

No, while it is a combustible product, it lacks the volitility of other products. It actually CAN be used, and will light and burn pretty nicely, BUT your cigarettes will taste funny! Someone 'borrowed' some fluid from me, not noticing I had marked the can "WD-40" with a marker. He had to get new cotton and a new wick for his lighter!